It would make far more sense when creating a custom GPT, to be able to link to documents which could be updated without replacing the documents with new ones.
Like OpenAI’s own “Google Drive”, without having to use Google Drive.
Since ChatGPT is primarily a text processing engine, this ability could be limited to formats that could be easily edited within the ChatGPT interface (i.e. plain text, or a simple markup language).
I just seems like the next natural step of ChatGPT would be able to build a sort of wiki of information that both ChatGPT (i.e. custom GPTs) can use as well as exist as a static piece of data that could be exported to a website.